LTC1514-3.3 Datasheet, PDF (4/8 Pages) Linear Technology – Step-Up/Step-Down Switched Capacitor DC/DC Converters with Low-Battery Comparator

LTC1514-3.3/LTC1514-5
TYPICAL PERFORMANCE CHARACTERISTICS
LTC1514-5 Step-Down Mode
Load Transient Response
LTC1514-5 Step-Up Mode
Load Transient Response
V_OUT
AC COUPLED
100mV/DIV
I_OUT
50mA/DIV
50mA
0mA
V_OUT
AC COUPLED
100mV/DIV
I_OUT
50mA/DIV
V_IN = 8V, V_OUT = 5V, C_OUT = 10µF, T_A = 25°C
1514 G10
V_IN = 3.3V, V_OUT = 5V, C_OUT = 10µF, T_A = 25°C
1514 G11
BLOCK DIAGRAM
C1 ^–
C1 ⁺
V_IN
SHDN
STEP-UP/STEP-DOWN
CHARGE PUMP
650kHz
OSCILLATOR
V_OUT
LBO
LBI
1.145V
V_REF
GND
1514 BD
PIN FUNCTIONS
SHDN (Pin 1): Shutdown Input. A logic low on the SHDN
pin puts the part into shutdown mode. A logic high
(V_SHDN ≥ 1.6V) enables the charge pump regulator. At
high V_IN voltages, the SHDN pin may still be controlled
with 3V logic without causing a large rise in V_IN quiescent
current. The SHDN pin may not float; connect to V_IN if
unused.
LBO (Pin 2): Open-Drain, Low-Battery Comparator Out-
put. This pin will pull low whenever the voltage on the LBI
pin is less than the internal reference voltage (1.145V typ).
LBI (Pin 3): Low-Battery Comparator Input. The voltage
on this pin is compared to the internal reference voltage
(1.145V). The LBO output will sink current when the
voltage on the LBI pin is less than 1.145V typ. The low-
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